Printing telegraph system



Feb. 0 14925" G. s. VERNAM PRINTING TELEGRAPH SYSTEM Filed Jan. 29', 1915 3 Sheets-Sheet "I INVENTOR. 6. 15. Vl lzwm BY I A TTORNEY Feb, 10, 1925.

G S. VERNAM PRINTING TELEGRAPH SYSTEM 5 Shets-Sheet a Filed Jan. 29,; 1918 IN V EN TOR. G. 51 Vernam BY ATTORNEY G. s. VERNAM PRINTING TELEGRAPH SIS'IElvl Filed Jan. 29, 1913 3 Sheets-Sheet 3 W Em QN I INVENTOR. G. S. Vernam BY ATTORNEY Patented Feb. 10, 1925.

UNITED STATES PATENT OFFICE.

GILBERT SANFORD VERNAM, OF-BROOKLYN, NEW YORK, AS SIGNOR T AMERICAN TELEPHONE TELEGRAPH COMPANY, A CORPORATION OF NEW YORK: i

PRINTING TELEGRAPH srs'rnlvr.

Application filed January 29, 1918. Serial No. 214,302.

To aZZto-hom it may concern:

Be it known that I, GILBERT S. VERNAM,

residing at Brooklyn, in the county of Kings and State of New York, have invented oertain Improvements in Printing Telegraph Systems, of which the following is a specification. I a

This invention relates 'to printing telegraph' systems and more particularly to auxiliary or' break-in signals for use in connection with such systems.

In printing telegraph systems it. is 'dey sir-able practice to arrange two or more stations upon a single lineso that when one station istransmitting the other station or stations may all receive and print the message transmitted. In such organizations exigencies may arise rendering it desirable that a receiving station be able to interrupt :0 transmission of a message from the sending station and transmit to the sending station a signal or message. For example: the ,transmittedmessage may not be properly received at one station. In such a caseit is desirable. that such a receiving station be able to stop the transmission of-signals from the sending station and obtain control of the line for the purpose of sending to the transmitting station .a message or signal indicating that a part or all of the transmitted the objects of this invention to provide means whereby the above results may beattained although other and further objects 3 will appear from the detailed description hereinafter given.

In accordance with 'this invention the aboveresults may be obtained by providing at each station means whereby, while a message is being received, an operator at any receiving station maycause a change in the electrical condition. of the line such that the transmitter at the transmitting station will stop sending and a special signal will be given to '.indicate that a receiving station desires to break in upon the line. At the.

message should be repeated. It is one of,

which, respectively, constitute circuit diagrams or three different forms of the invention.

Referring to Figure 1, the transmitting and receiving apparatus of one station is shown. The transmitting apparatus comprises a transmitter 10 conventionally indicated as, comprising five contacts 11, 12, 13, 14 and 15, which may be selectively op-' erated to determine the code for the transmission of any character or signal. As the transmitter is well known land forms no part of the present invention, the details thereof are not shown. Associated with the, transmitter 10 is a sending distributor 11 comprising an arm 12 which intermittently rotates over a pair of rings 13 and 14'. Outer ring 13 comprises a plurality of segments, the segments numbered 1 to 5 being selective segments and corresponding respectively to the contacts ofthetransmitter.

A starting segment S and a stopping segment SP are also included in the outer ring.

The brush arm 12 is arrangedto be released by a start magnet 15 under the control of a start relay 16 the circuit of which is con trolled by a contact between the brush arm 12 and the armature of the'start magnet 15 and a contact 17 actuated sequentially with the actuation of the contacts 11 to 15 of the transmitter. v

The receiving arrangement comprises a receiving printer conventionally indicated at 20 which may be of any well known type, and as it formsno part of the present invention the details are not shown. The re- .ceiving printer is associated with a receiving'distributor'21 comprising a brush arm 22 adapted to be intermittently rotated over a pair of rings 23 and 24. The outerring 23 comprises aplurality of segments, five of which numbered 1 to- 5 are selecting segments and correspond to the similarlynumbered segments of the sending distributor -11..- The outer ring also. includes a starting segment S, a printing segment P and a segment for enabling the operator at any receiving station to operate the break-in signal and stop the sending transmitter; The brush arm 22 is arranged to be released byte": starting magnet 25 under the control of start relay 26; the start relay in turn is controlled by the line relay 27 which relays the transmitter impuses ;to' the receiving apparatus. A break key BK comprising contacts 28 and 29 is associated with the receiving,

apparatus and is arranged to open the line L when operated, thereby causing the line relays of the various stations to be deener-- gized. The line relay being deenergized at the instant when the brush arm 22 is passinq over thesegment B, a circuit is closed through the break relay 30 which operates to cause a lamp or other indicating appara-' tus 31 to function and also operates to stop the operation of the sending apparatus by holding open the circuit of the start relay 16.

- The sending and receiving apparatus are associated with a line L and it will be noted that the contact 28 of the break key BK, the line relay '27 and the contacts of the transmitting apparatus are in series with the line L. The line. is normally closed through the upper contact of the start relay 16, of the sending apparatus, which contact is opened upon theactuation of the start relay 16 so that during the rotation of the brush arm I 12 over'the rings ofthe distributor the open or closed condition of the line is determined scribed so that the normally closed line circuit will extend serially through the several stations.

The invention will no be clear from a description of the operation. Assuming that the station shown in Figure 1 is send ing, the transmitter 10 will be actuated either by depressing a key or by means of a tape, thereby closing'certain of the contacts 11 to 15 inclusive, depending on the code impulses to be transmitted, the contact 17 being also operated. The actuation of the contact-17 closes a circuit from battery over the lower back contact of break relay 80, through the upper winding o'f start relay 16 of the sending distributor, contact 17, armature of start magnet 15, brush arm 12 and segment .32 of .the inner ring of the distributor 11 to ground. The start relay 16 is energized and at its lower front contactcloses a lockmg circuit from battery over thelower back contact of break relay 30, upper back contact of stop relay 33, lower front contact and lower winding of start relay 16 to ground. At the same time a circuit isvclosed for the start magnet 15 from'battcry over the lower back contact of break relay 30, upper back contact of stop relay 33, lower front contact of start relay 16, winding of start magnet 15, start segment S of the outer ring, through the'brush of the arm 12 and the segment 32'of the inner ring of the'distributorxto ground. The'start magnet 15 is energized over this circuit and releases the brush arm 12 which begins to rotate over of its rotation.

' l v x the rings of the distributor. As soon as the arm passes from the start segment S, \the circuit of the start magnet is opened and the armature of said magnet is released in order to stop the brush arm at the end The energization of the start relay 16 at' its upper contact opened the normally closed lne circuit L thereby opening the circuit of t 1e line relays such as 27, of all the stations associated with the line. -This releases-the brush arms of the receiving distributors of allthe stations in a manner hereinafter described. As the brush arm-12 of the brush 12 rotates over the first selecting segl ment, the line L will be closed over the con tact 11, the first'selecting segment of the outer ring 13, the brush of the arm-1'2 and segment 34 of the inner ring of the distributor, thereby transmitting a closed cir cuit impulse as the first selecting impulsel As the brush arm passes from the first selecting segment .tothe second selecting segment the control of the line L is transferred to the contact, 12. As this contact is open no current will betransmitted over the line during the period corresponding to" the second selecting impulse. The brush now rotates over the third selecting segment of the distributor and the line is closed over I the contact 13, the third selecting segment, the brush of the arm 12 and the segment 31 to transmit a closed circuit impulse. This will be followed by an opening of the circuit as the brush passes over the fourth selecting segment and the last selecting im- I pulse will be a closed circuit impulse as the brush passes over the fifth selecting segment, the line being at this tune closed over the contact 15' of the transmitter, the fifth selecting segment, the brush of the arm 12 'and the segment 3-1.

and at its upper contact opens the locking circuit previously traced through the lower winding of the start relay 16 thereby deenergizing the start relay. Upon the deenergization of .thestart relay the line is closed over the upper back contact of said relay thereb transn'ntting a closed circuit stopping impulse to the various line relays of the stations associated with the line. The l transmitter is now ready to transmit a second series of code impulses for the next character.

will be recalled that during the period corresponding to first or'starting impulse the line was open circuited due to the energization of the start relay 16. In response to this condition all of the line relays such as 27 at the various stations are deenergized. The deenergization of the line relay 27 closes a circuit from ground over the back contact of said relay, through the Winding of the start relay 26, over start segment Set the outer ring of the receiving distributor, over the brush of the arm 22 and the segment 36 of the inner ring of the. distrlbutor to battery. The start relay is energized over this circuit and at its lower front contact closes a locking circuit from ground through its wlndingand over the start segment S, the

brush of the arm .22 and segment 36 to battery. Start relay 26 at its upper front contact closes a circuit through thestartmagnet 25 which upon being energized attracts its armature and releases the brush arm 22 which begins to rotateover the segments of.

the'distributor. As soon as thebrush passes from the start segmentiS the locking cir-' 'c-uit just traced through the winding of the start relay 2.6 is opened sothatthe start relay 26 and start magnet -25.are deenerized, and the armatureiofthelatter is released to. engage and stop the arm 22 at the completion of its rotation. r

Upon leaving the segment S the arm passes over the first selectin' segment of the receiving distributor. At. t is moment the first selecting impulse is. being received from the'line at each of the receiving stations. It Will be remembered the t the first seleetingimpulse was. a closed--circuitampulse and accordingly the line relay and similar relays at other stations will be ener gized. Thiscloses a ClI'OllltOYBIflthQ front" contact of the'l-ine rela 27,"segm ent 37 of the distributor, the brus i of arm '2l2 and the j first selecting segment through'a selecting relay or other apparatus (not shown) in the receiving printer 1 20 and to la battery (not shown). As the varm continues in its rotation it 3 passes over the second selecting segment at the moment corresponding to the second selecting impulse'fd-uring which, it will be remembered, the line was open circuited. The line relay is therefore deenergized at this moment and no circuit is completed 'overzthe second selecting segment of the receiving distributor to apparatus in the receiving printer. The armature of the line relay 27 is resting upon its back contact but no circuit changes are produced 1 thereby. The arm.22 continues rotating,

of the distributor to start the printing operation so. that the character determined by the five selecting impulses is printed. Before the brush reaches the segment B of the receiving distributor'the seventh or stop impulse has'been"transmitted to the line L by the sending apparatus. This impulse, it will be remembered, was a closed circuit impulse, so that the line relay 27 and the similar line relays at other stations are energized thereby preventing the completion of a circuit through the lower winding ot'the break relay 30 over the segment B. After passing from the segment B the arm 22 is engaged by the retracted armature of the start magnet 25 and comes to rest with its brush upon the. start segment S. The apparatus is now ready to respond to another sefiies of code impulses.

Assuming now that the operator at some other station along the line L desires to break in l for any purpose, such operator will operate the break key BK at his station. The contacts 28 of the break keys at the several stati'ons'are all serially connected in the line circuit L and the operation of thebreak key at any station consequently opens the line circuit. relays such as 27 at all stations will be de- Therefore, the line 1'05;

energized as long as the break key BK is held open at any station and as soon as the brush arms 22 of the receiving distributors at the'var ous station's pass over the segments B a circuit iscompleted' at the station shown in Figure 1 over back contact of the linei.' -.elay 27, through the lower Winding of the break relay 30, over. segment B, the brush of the arm 22 and segment 36 to battery. Similar circuits are completed at all otthe stations with the result that the break relay at each station is energized. The energization of the break relay 3O closes a locking circuit from ground over its upper figont contact through its upper winding" t rough lamp 31. contact of the release key. 'RK and contact 29 of the break key BK to battery. Similar locking circuits are'conv pletedat all stations except the station at which the break key BK was. operated. The locking circuit is not completed at such station since the contact 29 of the breakkey BK is open.

The locking circuit lights the signal lamp 31 at the station of Figure 1 and similar signal lamps at other stations with the eXcep-- tion of the station at which the break key BK was operated. The functioning of the lamp 31 at the signal station-shown in Figure 1 indicates to the operator at that station that another operator-desires to obtain transmit a message as soon as he releases the break key KB as the line is now in normal condition. The operators at all stationswhere the signal lamps, such as 31, are caused to glow; may operate their release keys RK thereby opening, the locking circuit through the upper winding of the break relay and the signal lamp. The deenergization of the break relay 30 at the transmit ting station of Figure .1 restores the starting circuit of the start relay 16 to normal by applying battery thereto over its lower back contact. The transmitting apparatus is now in normal condltionand the operator at the station atgFigure 1 may actuate the transmitter as soon as the station whichis 'now transmitting ceases to send impulses.

It will be noted that in thearrangement just described the signal lamp corresponding to'the lamp 31 of Figure 1 is actuated at all stations except the station where the break key BK is actuated, It is not necessary to operate the break-in signal at any station except the transmitting station. Accordingly, an arrangement is shown in Figure 2 whereby the break relay and the corresponding signal lamp are operated at the sending station only. The apparatus is substantially the same as that described in connection with Figure-1, except that the initial circuit of the break relay is completed over a segment B of the outer ring of the sending distributor instead of the receiving distributor. As the brush arm of the sending distributor of the transmitting station is the only sending brush arm that isrotating, the break relay will be operated .at the sending station only. i a

The normal operation of sending and receiving in Figure 2 is the same as that already described in connection with Figure 1 and need not be further discussed. If, how'- ever, while the station shown in Figure 2 is transmitting, an operator at another station depresses the break key BK at that station the line circuit is held open and the line relays at the various stations remain deenergized. As the brush .arm 12-of the sending distributors at such stations are at rest. Re-

lay 30 completes a locking circuit from ground over its lower front contact and through its lower winding, through the lamp 31 andover the contacts of release key RK to battery. The lamp 31 now glows to indicate to the operator at the transmitting station that another operator desires to ob.- tain control of the line. The actuation of the break relay 30 at its upper contact opens the starting circuit of the start relay 16 so that the transmitting distributor cannot be released. Asfsoon as the operator observes the signal of the lamp 31 the release key RK may be actuated to restore the lamp'and the break'relay 30 to normal. I

Another modification is illustrated in Figure The apparatus in Figure 3 is substantially the same as that already described but differs therefrom in that the circuit of the break relayBO is controlled over a segment B of the sending distributor and a cooperating segment B of the receiving distributor which is angularly displaced relative to the segment B of the sending distributor. In the normal operation of the apparatus the brush arms 12 and 22, of the sending and receivingdistributors respectively, rotate substantially 'in synchronism at the sending station so that they do not simultaneously pass over the segments B of the two distributors and consequently the circuit ofthebreak relay 30 is not completed. If. however, while the station illustrated in Figure 3 is transmitting, the operator at another station should depress the break key at such station the line circuit would be held open and the line relays, such as 27, at the various stations will remain deenergized. The brush arm 22 is so arranged that 1t rotates at substantially the same speed as the brush arm 12. approxireceiving distributor engages with the start segment Supon nearing the completion of its rotation the start relay is energized overa circuit from the back contact of the line relay, through the winding of the start 50 v '1. Ina printing telegraph system, a line path ofthe arm 22 beforethe arm comes I to rest; "The arm 22 therefore rotates continuously so long as the break key remains depressed. Since the arm 22 is rotating continuously and the arm 12 stops for an instant at the end of each rotation, the arm 22 gains with respect to the arm 12 so that after a"- fe w revolutions the. two arms W-lll be rotating at such relative angles with respectitocach other that-the brushespass over the segments B of the sending and receiving distributor at the same instant,

thereby completing a circuit from ground over the segment 32, brush of arm 12, segment B, lower winding of the break relay 30, segment B of -the receiving distributor,

the brush of arm '22 and segment 36 tobattery.- This circuit is. completed at the transmitting station only, as the brushes of the sending distributors at the other stations are not rotating. The actuation of the break relay 30 completes a locking circuit over its upper contact and through its upper wind ing, through the signal la'mp'31 and over the contact'of the release key'RK to battery,- indicating to the qperator' at the sending station that another operator desires to obtain control of the line. Break relay 30 at its lower contact opensthe circuit of the starting relay 16, thereby preventing further actuation of the sending distributor.

It will beseen that by means of the ar- "1 rangements or. this invention a printing telegraph systemvhas} been produced which is very flexible-ilrsov asits method of operation is concernedso that any operator,

at any station may-arm time-obtain conn01 of the line for sending purposes without materially interfering'with thenormaloperation of the system. It Willi-also be obvious that the general principles-herein disclosed may be used in many other organizations Widely different from those illustrated without departing from the spirit of the inven- IVVhat is claimed is:

tion as defined in the appended claims.

with. said line circuit at one of said stations,

receiving printing apparatus associated with T said line circuitat another of said stations,

a-special signal at said first mentioned-station, a relay in said line circuit at said first mentioned station 'for controlling said special signal, said relaybeing responsive to impulses transmitted to operate receiving printingapparatus, meansat said last mentioned'station to open the line circuit, and

means whereby said special signal will be actuated in response to the opening of said printin' circuit, a plurality of printing telegraph stations, transmitting apparatus and receiving printing apparatus associated with said line "circuit at each station, the receiving printing apparatus at a receiving station being responsive 'to impulses transmitted by the transmitting apparatus atv a transmitting station, a special signal associated with said line circuit, a'relay associated with said line circuit for controlling said signal,

said relay being responsive to impulses transmitted from atransmitting apparatusto operate a receiving printing apparatus,

.means whereby the line circuit may be opened while impulses, are being transmitted,. and means whereby said speclal.

signal will be actuated in response to the opening of said line circuit but will not be actuated by the response of said relay to said impulses transmitted to operate receiving printing'app'aratus.

3. In a-printing telegraph system, a line circuit, a plurality of printing telegraph stations, transmitting apparatus associated with said line circuit at one of said stations, receiving printing apparatus associated with said line circuit at another of said stations, means at said last mentioned station to change the character of said line circuit, a relay at said first mentioned station responsive to impulses transmitted to operate, a receiving printing apparatus, a special signal controlled by said relay and unoperated by the response offsaid relay to such transmitted impulses, but operated tions, receiving printing apparatus associated with said line circuit at anotherof said f'stations', means at said last mentioned station to open? the line circuit, a relay at said first mentioned station responsive to impulses-transmitted to operate a receiving apparatus, a special signal controlled y said relay and unoperated by the response of said relay to such transmitted impulses, Said signal being operated by said lay when the line circuit is opened by saidline circuit opening means.

5. In a printing telegraph system, a line circuit, a plurality of printing telegraph stations associated with said line circuit, a

by said relay when the character of the ill) rotary distributor at each station comprismg a brush rotatable over a plurality of segments, a transmitter associated with the distr butor at one statlon, a receiving printer associated with the distributor at a secondstation, means responsive to the operation of the transmitter to transmitan impulse over the brush of the distributor at said first station to release the brush of the distributor at the second station, whereby the brushes rotate over corresponding segments at thetwo stations to transmit imsegments, a transmitter associated with the distributor at one station, a receiving printer associated with the distributor at a second station, means responsive to the operation of the transmitter to. transmit an impulse over the brush of the distributor at said first station to release the brush of the distributor at the second station, whereby the brushes rotate over corresponding segments at the two stations to transmit impulses from-the transmitter to the receiving printer, a, special signal atsaid first station unresponsive to said impulses, and means at the second station to so change the character of the line circuit during the transmission of impulses as to operate said special signal.

7. In a printing telegraph system, a line circuit, a plurality of printing telegraph stations associated With said line circuit, a rotary distributor at each station. compris ing a brush rotatable over a plurality of segments, a transmitter associated with the distributor at one station, a receiving printer associated with the distributor at a second station, means responsive to the operation of the transmitter to transmit an impulse over the brush of the distributor at said first station to release the brush of the distributor at the second station, whereb v the brushes rotate over corresponding segments at the two stations to transmit impulses from the transmitter to the receiving printer, a spccial signal at said first station unresponsive to said impulses, and means at said. second station to open the line circuit to operatesaid special signal.

8. In a printingtelegraph system, a line circuit, a pluralityotprinting telegraph stations associated with said line circuit. a rotary distributor at each station comprising a brush rotatable over a plurality of ments, a transmitter associated with the distributor at one station, a receiving printer associated with the distributor at a second station, means responsible to the operation of the transmitter to transmit an impulse over the brush of the distributor at said first station to release the brush of the distributor at the second station, whereby the brushes rotate over corresponding segments at the two stations to transmit impulses from the transmitter to the receiving printer, a special signal at said first station unresponsive to said impulses, and "means at the second station. to so change the character of the line circuit during the transmissionof impulses as to operate said special signal and stop one of said distributors.

9. In a printing telegraph system, a line circuit, a plurality of printing telegraph stations associated with said line circuit, a rotary distributor at each station compris ing abrush rotatableover a plurality of segments, a transmitter associated'with the distributor at one station,,a receiving printer associated with the distributor at a second station, means responsive to the operation of the transmitter to transmit an impulse over the brush of the distributor at said first station to release the brush or the distributor at the second station, whereby. the brushes. rotate over 'corresponding segments at the two stations'to transmit impulses from the transmitter to the receiving printer, a special signal at said first station :unresponsive to said impulses, and means at the second station to open the line circuit to operate said special signal and stop one of said distributors.

10.111 a printing telegraph system. a line circuit, a plurality of printing 'telegraph stations associated with said line circuit, a rotary distributor at each station comprising a brush rotatable over a plu- 'ality of segments, a transmitter associated" with the distributor at one station, a receiving printer associated with the distributor at a second station, means responsive to the operation of the transmitter to transmit a starting impulse over the brush of the distributor at said first station to release the brush ofthe distributor at the second station, whereby the brushes rotate over corresponding segments at the two stations to transmit character determining impulses from the transmitter to the receiving printer, said starting impulse taking no part in determining the character to be printed, and means at said second station to change the electricalcharacter oi the line to stop one Bream distributors.

ll. In a printing telegraph system. a line circuit. a plurality of printing telegraph stations associated with said linc circuit, a. rotary distributor at each station comprising a brush rotatable over a plurality of segments. a transn'iitter associated with the distributor at one station, a receiving printer associated with the distributor at Ill) said first station.

starting impulse over the brush of the dis.- tributor atsaid first station to release the brushof the distributor at the second sta-. tion, whereby the brushes rotate over corresponding segments at the two stations to transmit character determining impulses from the transmitter to the receiving printsaid starting impulse taking no part in. the character to be printed,

said firststation to release the brush of the distributor at the second station, whereby the brushes rotate over corresponding segments at the two stations to'transmit char-,

acter determining impulses from the transmitter .to the receiving printer, said starting impulse taking no part in determining the character to be printed, and means at said second station tostop the distributor at 13, In a printing telegraph systenna line circuit, a plurality of printing telegraph stations associated-with said line circuit, a"

rotary distributor at each station comprising a brush rotatable over a plurality of segments, a transmitter associated with the distributor at one station, a receiving printer station, means responsive to the operation I of the transmitter to transmit a starting impulse over the brush of the-distributor at said firststationi to release the brush of the distributor at the second station, .whereby the brushes rotate over corresponding segments at the two stations to transmit character determining impulses from -the transmitter to the receiving printer, saidv starting impi lse taking no part in deter-' mining the character to be "printed, and means-to alter the electrical-character of the line in such manner as to stop the distributor at said first station.

14. In a printing telegraph system, a line circuit, a plurality of printing telegraph stations associated with said line circuit, a

rotary distributor at each station comprise ing a brush rotatable over a plurality'of segments, a transmitter associated with the distributor at onstation, a receiving printer I associated with the distributor at a second station, means responsive to the operation ozt the transmitter "to transmit a starting .said first station.

,the brushes rotate over corresponding segments at the two stations to transmit character determining impulses from the transmitter to the receiving printer, said starting impulse-taking no part in determining the character to be printed, and means to open I the line circuit to stop the distributor at 15. In a telegraph system, a line circuit, a plurality of telegraph stations associated with said line circuit, a' rotary distributor at each station, a transmitting apparatus associated with the distributor at one station and a receiving apparatus associated with .the distributor at a second station, means responsive to the operation of the transmitter to transmit a starting impulse from the d stributor at said first station to set into operation the distributor at the second sta-.

tion, whereby signal determining impulses may be transmitted from the transmitting apparatus over the-line and distributors to the receiving apparatus, said starting iinpulse taking no part in determining the signal transmitted, and means controllable from one station to stop the transmission 5 from the distributor at the other station. #16. a telegraph system, aline circuit, a plurality of telegraph stations associated with said line"cir'cuit, a rotary'distributpr at each station, a transmitting apparatus assoctatedwith the distributor-at one. station and a receiving apparatus associated with vthe distributor at a second station, means responsive to the operation 'offthe transmitter to transmit a starting impulsefromthe distributor atsaid first station to associated with the distributor at a second set into ,operationthe distributor at the second station, whereby signal determining impulses maybe transmitted from the-transmitting apparatus over: the line and distributors to the receiving apparatus, said starting impulse taking no part in deter-- -mining the signal transmitted, and means at the-second station to stop the distributor at i the first station.- C I I I 17. In a telegraph system, a line circuit, a plurality of telegraph stations associated with said line circuit, a rotary distributor at each station adapted to make a complete revolution at a uniform rate of travel, a

transmitting apparatus associated with thedistributor at one station and a receiving apparatus assoc ated with the distributor at a second station, means responsive to the operation of the transmitter-to transmit a starting impulse from the distributor at said first station to set into operation the distributor atethe second station, whereby signal determining impulses may be transmitted from the transmitting apparatus over the line and distributors to the receivmitted, and means to open the line circuit to stop one of said distributors.

18. In a printing telegraph system, a line circuit, 'a plurality of printing telegraph stations associated with said line circuit, a transmitting apparatus at one station,- a receiving printing apparatus at a second station, means responsive to the operation of the transmittingapparatus for transmitting a starting impulse to condition said receiving apparatus for receiving signals, said impulse taking no part in determining the signals to be transmitted, and means at said second station to stop the transmitting apparatus at said first station.

19. In a printing telegraph system, a line circuit, a plurality of printing telegraph stations associated with said line circuit, a transmitting apparatus at one station, a receiving printing apparatus at a second station, a special signal at said first station. a relay associated with said line circuit for controlling said signal, said relay being responsive to impulses transmitted from a transmitting apparatus to operate receiving printing apparatus, means at said first station controlled by said relay to stop said transmitting apparatus at said first station and operate said special signahsaid .means being non-responsive to the actuation of said relay by impulses transmitted over the line to operate a receiving printing apparatus, and means ,at said second station whereby said 'last mentioned means may be controlled by said relay to stop the transmitting apparatus at said first station and operate said special signal.

20. In a printing telegraph system, a line circuit, a plurality of printing telegraph stations associated'with said line circuit, a rotary distributor at each station comprising a brush rotatable over a plurality of segments, a transmitter associated with the distributor at one station, a receiving printer associated with the dist-ribsutor at a second station, means responsive to the operation of the transmitter to transmit. an impulse over the brush of the distributor at said first station to release the brush of the distributor at the second station, whereby the brushes rotate over corresponding segments at the two stations to transmit impulses from the transmitter to the receiving printer, a special signal at said first station, and means at said second station to stop the distributor at said first station and operate said signal.

21. In a printing telegraph system, a line circuit, a plurality of printing telegraph stations associated with said line circuit, a rotary distributor at each station comprising a brush rotatable over a plurality of segments, a transmitter associated with the distributor at one station, a receiving printer associated with the distributor at a second station, means responsive to the operation of the transmitter to transmit an impulse over the brushof thedistributor at said first station to release the brush oi. the distributor at the second station, whereby the brushes rotate over corresponding segments at the two stations to transmit im- .rotary distributor at each station comprising a brush rotatable over a plurality of segments, a transmitter associated with the distributor at one station, a receiving printer associated with the distributor at a second station, means responsive to the operation of the transmitter to transmit an impulse over the brush of the distributor at said first station to release the brush of the distributor at the second station, whereby the brushes Zrotate over corresponding segments at the two stations to transmit impulses from the transmitter to the receii 'ing printer, a special signal at said first station, and means to open the line circuit to stop the distributor at said first station and operate said signal. I

23. In a telegraph system, a line circuit. a plurality of telegraph stations associated with said line circuit, a rotary distributor at each station, a transmitting apparatus associated with the distributor at one station and a receiving apparatus associated with the distributor at a second station, whereby signals may be transmitted fronrthe transmitting apparatus over the line and distributors to the receiving apparatus, a special signal at said first station, and means at the second station to stop the distributor .at thefirst station and operate said signal.

'24. In a telegraph system, a line circuit.

a plurality of telegraph stations associated transmitting apparatus and a receiving printer associated with each other by means of a normally closed line circuit, a special lit] signal associated with said transmitting apparatus, said transmitting apparatus being adapted to transmit a code combination consisting of a plurality of open and closed circuit conditions corresponding to'signaling impulses to operate said printer without operating said signal, and means whereby a circuit condition of the same characteras one of said circuit condltions correspond- 'ing tosignaling impulses may operate said signal. 1

26. In a printing telegraph system, a transmitting apparatus and a receiving printer associated with each other by means of a normally closed line circuit, a special signal associated with said transmitting apparatus, said transmitting apparatus be1ng adapted to transmit a code combination consistlng of a plurality of open and closed circuit conditions corresponding to signaling impulsesto operate said printerwithout operating said signal, and means Whereby a circuit condition of the same character as one of said circuit conditions corresponding to signaling impulses may operate said signal and stop said transmitting apparatus.

27. In a printing telegraph system, a

' transmitting apparatus and a receiving printer associated witlreach other by means of a normally closed line CIICIliiJ, a special signal associated with said transmittingapparatus, said transmitting apparatus being adapted to transmit a code combination consistlng ofa plurality of open and closed circuit conditions corresponding to signaling impulses to operate said printer without operating said signal, and means wherev by a circuit condition of the same'character as one of said circuit conditions correspond ing to signaling impulses may stop said transmitting apparatus;

' 28. In a printing telegraph system, a

line circuit, a transmitting apparatus and a receiving prlnter assoclated with said line circuit, said transmitting apparatus being adapted to transmit a 'SIICCQSSlOIl of groups of signals of varying characters to operate said receiving printer,-one signal of each group. being always of the same character, and means to change the character of said signal to stop the transmitter.

29. In a printing telegraph system, a line circuit, a transmitting, apparatus and a receivingprinter associated withsaid line circuit, said transmitting apparatus being adapted to transmit a succession of groups of signals of varying characters to operate saidreceiving printer, one signal of each group being always ofthe same character,

a special sign'al indicator associated with the transmitter, and means to change the character of said signal to operate said signal indicator.

30.v In a 'printingtelegraph system, a

line circuit, a transmitting apparatus and a receiving printer associated with said line circuit, a plurality of printing telegraph stations associated with said line circuit, an intermittently operating distributor each station, a transmitting apparatus associatedwith the distributor at one station,

and a receiving printer associated with the distributor at a second station, means responsive to the actuation of said transmita5 nal to the line and release both distributors,

ting apparatus to transmit a-starting sigmeans to transmit to the line a plurality of variable selecting signals followed by a.

stopping signal of uniform character, line relays at each station responsive to said s1gnals, a special signal indicator so 0011- trolled by the line relay and distributor at the first station that said signal indicator Wlll be actuated only when the character of the last or stopping signal is changed, and 395 means for changing the character of said signal.

32. In a printing telegraph system, a line circuit, a plurality of printing telegraph stations associated with said line circuit, an intermlttently operating distributor ateach station, a transmitting apparatus associated with the distributor at one station, and v a receiving printer associated with the distrlbutor at a second stat on, means responsive to the actuation of said transmitting apparatus to transmit a starting signal to the line and release both distributors, means to transmit to thelinea plurality ofvariable selecting signals followed by a stopping signal of uniform cha'racter,.line relays at each station responsive to said .signals, a special signal indicator at the first station, a relay for controlling said signal indicator, said relay being controlled by the tion and so arranged as to o erate said signal indicator only when the c aracter of the last or stop 'ing signal is changed, means for changing the character of the line relav and distributor at the first stasignal, and means controlled by said relay for preventing further actuation of the distributor when the character of said-signal is changedig 33. An electric circuit controlling systern comprising a translator, circuits to con-= trol the operation ofsaid translator, and

signal mechanism for said translator con-.

trolled by said circuits'cnly upon the continuanee of a signal in oneof said circuits 75 31. In a printing telegraph system, a line comprising a line, a translator controlled by signals on' the line and having means to cause stoppage thereof substantially at the termination of a cycle of'operations upon a chang'e from normal operating conditions on the line, and signal mechanism associated with said translator and operative only upon such cliange of-conditions on the line.

In testimony whereof, I have signed my name to this specification this 22nd day of 20 January, 1918.

GILBERT SANFORD YERNAM. 

